PolylineFromColumns patch

[skinkie]

This patch allows any non-spational database to produce linestrings from an aggregated function. The output from the database must(!) be sorted.

Usage: ​http://kinkrsoftware.nl/contrib/osm/motorway.ovf

Original/Latest patch: ​http://kinkrsoftware.nl/contrib/gdal/gdal-polylinepatch.diff

[Jukka Rahkonen]

The patch has not been applied or commented yet during these 7 years.

[Even Rouault]

I'm not sure this is really necessary

Consider points.csv : pt_id,way_id,x,y 1,1,2,49 2,1,3,50 1,2,-2,49 2,2,-3,50

Then with spatialite MakeLine() aggregate :

ogrinfo points.csv -sql "select way_id, makeline(makepoint(cast(x as float),cast(y as float))) from points group by way_id" -dialect sqlite

OGRFeature(SELECT):0
  way_id (String) = 1
  LINESTRING (2 49,3 50)

OGRFeature(SELECT):1
  way_id (String) = 2
  LINESTRING (-2 49,-3 50)

[Kyle Shannon]

That's good enough for me, I was just purging some OGR_SRS tickets. I will close, can be re-opened if need be.

[Even Rouault]

r29626 "CSV doc: add example how to build a LineString from a series of points (#2620)"